The present invention relates generally to railway hopper cars and in particular, to door apparatuses for discharging material from bottom discharge hoppers.
A number of different types of railroad cars exist for hauling various types of bulk cargo and for discharging that cargo. For example, railway hopper cars carry coal, sand, aggregates and other loose materials which materials can be discharged through openings in hoppers located beneath such cars.
Generally, the hopper cars have a plurality of hoppers which store the cargo in readiness for discharge. A variety of door apparatuses are utilized to open and close material discharge openings formed in the bottoms of the hoppers.
U.S Pat. Nos. 2,600,357 and 3,122,106 disclose a pair of longitudinally disposed discharge doors having a rectangular cross-section in which the width is relatively small compared to the length The discharge doors, pivoted about a generally horizontal axis, open and close an open bottom of a railway car. The doors are held closed by a latching mechanism and when the latch is released, the doors pivot downwardly and inwardly to allow the material to exit the car.
Also related to the door apparatuses shown in the aforementioned patents are the U.S. Pat. Nos. 3,596,608; 4,138,948 and 4,114,785 which disclose a pair of longitudinally disposed discharge doors having a rectangular cross section. The doors pivot downwardly and outwardly to allow material to exit a railway car. The doors have a flange which either outwardly extends at a lower end as in U.S. Pat. No. 3,596,608, or outwardly extends at an upper end as in U.S. Pat. No. 4,114,785, or upwardly extends at an upper end as in U.S. Pat. No. 4,138,948.
U.S. Pat. Nos. 3,173,381 and 2,729,503 disclose a pair of longitudinally disposed discharge doors for a railway hopper car having a "clam-shell" shaped cross-section.
U.S. Pat. No. 3,786,764 discloses a pair of longitudinally extending discharge doors for a commodity discharge car, having a rectangular cross-section with extending lip portions on both ends of an upper and lower surface. The doors abut one another in a closed position approaching the horizontal. When pivoted open, the doors are rotated to a generally vertical position.
U.S. Pat. Nos. 3,902,434 and 4,740,130 disclose longitudinally extending discharge doors for a railway hopper car. The doors have an inverted trapezoidal cross-section area with inclined portions on the upper surface near an outer edge. The doors abut one another in a closed position approaching the horizontal. When pivoted open, the doors are rotated to a generally vertical position.
U.S. Pat. No. 4,262,601 discloses longitudinally extending inner and outer discharge doors. Each outer discharge door includes a longitudinal plate appropriately secured to a longitudinal extending channel at an inner edge and including a longitudinally extending rigidifying flange portion at an outer edge. Each inner discharge door includes a longitudinal plate appropriately secured to a pair of transversely spaced longitudinally extending channels. Each door includes a pair of longitudinally spaced stiffeners.
U.S. Pat. No. 4,452,149 discloses a pair of longitudinally extending bottom discharge doors having an arcuate door face plate held between door and walls having a triangular configuration. Each discharge door is further defined by a top and bottom wall having a centrally located partial cut out. Spaced gussets are attached intermittently to the door face plates and the top and bottom walls to provide stiffness.